86 THE PALM-STEM : 



of it from more distant phenomena, I am fully aware 

 that this proceeding can claim no certainty, but at most 

 a certain degree of probability ; I nevertheless hope that 

 such a mode of considering it will not be altogether use- 

 less. In the first place it has to be inquired, whether a 

 developing vascular bundle always grows in one direction, 

 or whether cases do not occur where its two ends become 

 elongated in opposite directions. In my opinion, the 

 latter case undoubtedly occurs, especially at the point of 

 insertion of a root upon a Monocotyledonous stem, and 

 of a branch of one of these roots upon the main trunk. 

 In both these cases, and especially distinctly in the latter, 

 we see vascular bundles originate in the cellular node in 

 which the formation of the root begins, the end of which 

 toward the point of the root, increases in length with the 

 further growth of the root, while the other end penetrates, 

 in the opposite direction, into the stem or primary root. 

 In an analogous manner, as is again to be observed more 

 clearly in the Monocotyledons than in the Dicotyledons, 

 the bud which is developing into a leafy branch, also 

 possesses its proper system of vascular bundles, inde- 

 pendent of that of the stem, the lower extremities of which 

 pass into the stem, and spread themselves out over a lesser 

 or greater portion of its ligneous mass. Now, these vas- 

 cular bundles are nothing else than the inferior extremi- 

 ties of the vascular bundles of this branch, and the most 

 ready supposition, on seeing these fibres passing over into 

 the stem, is that they have been developed from above 

 downwards. To this explanation, which immediately pre- 

 sents itself, it may certainly be objected, that the fact of 

 the passage of that vascular bundle into the stem, does 

 suffice to prove that this is perfected in the direction from 

 above downward, for the formation of that vascular bundle 

 in the stem itself may be caused by the presence of the 

 branch, through the attraction it exerts on the sap-bearing 

 substance of the stem, and it may grow from the stem 

 upward into the branch. But the direction which the 

 fibres lying beneath the rind of Monocotyledonous stems 



